Electrochemical elements, such as a lithium battery, an electric double layer capacitor, a lithium-ion capacitor and a molten salt battery, have been widely used as power supplies for portable microelectronics such as mobile phones and laptops, or for electric vehicles (EV).
For these electrochemical elements, generally, an electrode in which a mixture layer containing an active material is formed on a metal foil is used. For example, in the case of a positive electrode for a lithium secondary battery, as shown in FIG. 4, an electrode 31 for a lithium secondary battery, in which positive electrode mixture layers 33 containing a positive electrode active material such as a lithium cobalt oxide (LiCoO2) powder, a binder such as polyvinylidene fluoride (PVDF) and a conduction aid such as a carbon powder are formed on both surfaces of a current collector 32 made of an aluminum (Al) foil, is employed, and such an electrode 31 for a lithium secondary battery is produced by applying a positive electrode mixture in a slurry form obtained through addition and mixing of a solvent onto the current collector 32 made of an aluminum foil and drying the resulting coating film (e.g., Patent Literature 1).
Further, as a means of improving an output in the electrochemical element, methods, in which plural thinned electrodes are layered or an electrode having a larger area is wound into a roll, are generally employed.